I have this circuit and I am trying to determine Ic and VCE and operation mode. I am not sure if I am doing this correctly. Here is what I did:

I am given beta = 100 and VBE = 0.715v

I said the nod at the emitters is -0.715v therefore the emitter current is:

\(I_{E} = \frac{-0.715v - (-15v)}{180x10^{3}\Omega} = \frac{79x10^{-6}A}{2} = 39.7\mu A\)

The collector current is:

\(I_{c} = I_{E}\alpha = (39.7x10^{-6})(0.99) = 39.3\mu A\)

\(V_{CE} = V_{CC} - I_{C}R_{C} + V_{E} = 5v - (49.9x10^{3}\Omega)(39.3x10^{-6}\mu A) + (-0.715v) = 2.32v\)

The transistors are in forward-active mode.

 

Check your signs carefully. Vce = Vc - Ve, not Vc + Ve

 

Just to make the point - everything other than Vce looks fine.

 

Thanks. I am not sure why I put the + instead of the -.